Library of Congress Call Numbers   Tags: general_information_sources, science_general  

Watch a video, created for UM students, which explains LC call numbers.

Here's a list of all LC subject classifications

These classifications determine the first two lines of the call number.

When you find a book or journal in Mirlyn, you may see that different UM libraries list different call numbers for it.

Don't worry. No one made a mistake. Once upon a time, the different UM libraries had good reasons for cataloging differently. Here's an example: Volumes of the journal Applied and Environmental Microbiology can be found in three different libraries, with three different call numbers:

• AAEL   QR 1 .A66
  
• Science   QH 301 .A645
  
• Public Health  RA 421 .A76B
  

Also, for a long time UGL used LC call numbers for literature (P, PN, PR) but the Graduate library used Dewey Decimal (800s)

Most books in the U-M libraries are organized by Library of Congress call number.  Call numbers on books and journals appear either on the spine or on the front cover.  A line above the call number identifies the U-M library which owns the item.

The Library of Congress classification system uses alphabetical, numerical, and decimal order.

What do the parts of the call number mean?

Here's a sample call number, with explanation for each line:

QE -   letter line, describes general subject area; alphabetical order

862 -  number line, narrows subject area; numerical order

.D5 -  cutter line, usually specifies author or key word(s) from title; alphabetical then decimal order

H644 - 2nd cutter line (if present*) also in alphabetical then decimal order

1977 - year of publication, numerical order

* If there are two cutter lines, the first one usually further narrows the subject area and the second one reflects the author name or title words